The present invention relates to an optical measuring device, particularly using spectrophotometry. The invention is more particularly applicable to the field of nuclear chemistry.
During spectrophotometric measurements in the ultraviolet, visible or infrared ranges, use is made of equipment in which samples to be analyzed are placed in measuring cells and are traversed by an ultraviolet, visible or infrared beam.
In certain cases, it is difficult or even impossible to transfer the samples into the measuring cells. For example, this is the case with measurements performed in shielded enclosures with radioactive solutions. It is often impossible or at least difficult to install equipment in such enclosures.
An optical coupling device has been developed, which makes it possible to pass the light beam from a spectrophotometer to a sample to be measured and then return the light beam to the spectrophotometer after it has traversed the sample. This device is an assembly which is relatively complex with respect to the components and optical fibers. It only makes it possible to carry out a measurement at a single point (i.e. for a single sample).
In order to bring about an optimum utilization of the measuring instruments, it is sometimes of interest to carry out these measurements at several points using the same apparatus. For this purpose, an equipment has been designed, which uses mobile optical components, whose function is to deflect a light beam. This equipment is known from EP-A-177 387 (cf. also U.S. application Ser. No. 4, 820,045).
This known equipment leads to a problem of the reproducibility of the measurements, because the positioning of its mobile optical components is not perfectly reproducible.